B-theory old and new: on ontological commitment

The most important argument against the B-theory of time is the paraphrase argument. The major defense against that argument is the “new” tenseless theory of time, which is built on what I will call the “indexical reply” to the paraphrase argument. The move from the “old” tenseless theory of time to the new is most centrally a change of viewpoint about the nature and determiners of ontological commitment. Ironically, though, the new tenseless theorists have generally not paid enough sustained, direct attention to that notion. I will defend a general criterion of ontological commitment and apply it to generate a version of the new tenseless theory of time. I will argue that many of the extant versions of the new tenseless theory of time (specifically, all those which seek to identify tenseless truth-conditions of tensed sentences as a way out of apparent ontological commitment to tensed features of reality) are unsatisfactory because their general criterion of ontological commitment is inadequate. Those versions of the new tenseless theory which are adequate (specifically, those which identify tenseless truthmakers for tensed sentences) actually entail the criterion of ontological commitment that I defend, despite appearances to the contrary.